cropwidget.cpp

   1 /*
   2   cropwidget
   3   Copyright (C) 2009  Rafał Rzepecki <divided.mind@gmail.com>
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful,
  11   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13   GNU General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; if not, write to the Free Software
  17   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18 */
  19
  20 #include "cropwidget.h"
  21
  22 #include <QStackedLayout>
  23 #include <QMouseEvent>
  24 #include <QPainter>
  25 #include <QPaintEvent>
  26 #include <QResizeEvent>
  27
  28 CropWidget::CropWidget(QWidget *parent): QFrame(parent), _snapped(false)
  29 {
  30 }
  31
  32 void CropWidget::snap(bool snapped)
  33 {
  34   cropStart = QPoint();
  35   cropRect = QRect();
  36   const QList<QWidget *> widgets = findChildren<QWidget *>();
  37   if (snapped) {
  38     snapshot = QPixmap::grabWidget(this, contentsRect());
  39     foreach(QWidget *w, widgets)
  40       w->hide();
  41   } else {
  42     foreach(QWidget *w, widgets)
  43       w->show();
  44     QPainter painter(this);
  45     painter.eraseRect(contentsRect());
  46     update();
  47   }
  48   _snapped = snapped;
  49 }
  50
  51 void CropWidget::paintEvent(QPaintEvent *event)
  52 {
  53   QFrame::paintEvent(event);
  54   if (!_snapped)
  55     return;
  56
  57   QPainter painter(this);
  58   painter.setRenderHint(QPainter::SmoothPixmapTransform);
  59   painter.drawPixmap(contentsRect(), snapshot);
  60
  61   if (cropRect.isValid()) {
  62     QImage img(contentsRect().size(), QImage::Format_ARGB32);
  63     QPainter ppm(&img);
  64     ppm.fillRect(rect(), QColor(255, 255, 255, 200));    ppm.setCompositionMode(QPainter::CompositionMode_Clear);
  65     ppm.eraseRect(cropRect);
  66     painter.drawImage(contentsRect(), img);
  67   }
  68
  69   event->accept();
  70 }
  71
  72 void CropWidget::crop()
  73 {
  74   if ((!_snapped) || (!cropRect.isValid()))
  75     return;
  76
  77   int x = cropRect.x() * snapshot.width() / width();
  78   int y = cropRect.y() * snapshot.height() / height();
  79   int w = cropRect.width() * snapshot.width() / width();
  80   int h = cropRect.height() * snapshot.height() / height();
  81
  82   snapshot = snapshot.copy(QRect(x, y, w, h));
  83   cropRect = QRect();
  84   update();
  85 }
  86
  87 void CropWidget::mousePressEvent(QMouseEvent *event)
  88 {
  89   if ((!_snapped) || (event->button() != Qt::LeftButton))
  90     return QWidget::mousePressEvent(event);
  91
  92   const QPoint pos = toContents(event->pos());
  93
  94   cropStart = pos;
  95   event->accept();
  96 }
  97
  98 void CropWidget::mouseMoveEvent(QMouseEvent *event)
  99 {
 100   if ((!_snapped) || (cropStart.isNull()) || (!(event->buttons() & Qt::LeftButton)))
 101     return QWidget::mouseMoveEvent(event);
 102
 103   const QPoint pos = toContents(event->pos());
 104
 105   cropRect = QRect(cropStart, pos).normalized();
 106   update();
 107   event->accept();
 108 }
 109
 110 void CropWidget::mouseReleaseEvent(QMouseEvent *event)
 111 {
 112   if ((!_snapped) || (cropStart.isNull()) || (event->button() != Qt::LeftButton))
 113     return QWidget::mouseReleaseEvent(event);
 114
 115   const QPoint pos = toContents(event->pos());
 116
 117   cropRect = QRect(cropStart, pos).normalized();
 118   update();
 119   cropStart = QPoint();
 120   event->accept();
 121 }
 122
 123 QSize CropWidget::sizeHint() const
 124 {
 125   if (_snapped)
 126     return QSize(snapshot.size().width() + 2 * frameWidth(), snapshot.size().height() + 2 * frameWidth());
 127   else
 128     return QFrame::sizeHint();
 129 }
 130
 131 QSizePolicy CropWidget::sizePolicy() const
 132 {
 133   if (_snapped)
 134     return QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
 135   else
 136     return QFrame::sizePolicy();
 137 }
 138
 139 QPoint CropWidget::toContents(QPoint point) const
 140 {
 141   QPoint p = point - contentsRect().topLeft();
 142   if (p.x() < 0)
 143     p.setX(0);
 144   if (p.x() >= contentsRect().size().width())
 145     p.setX(contentsRect().size().width() - 1);
 146   if (p.y() < 0)
 147     p.setY(0);
 148   if (p.y() >= contentsRect().size().height())
 149     p.setY(contentsRect().size().height() - 1);
 150   return p;
 151 }